Diagonal conjucate is the only AP diameter that can be measured clinically. Can subtract 1.5 from that to get the obstretic conjucate. Index finger can be used to measure.
Then slide acorss pelvis to notice sacrum curves. whether sharp or not. And then side walls..whether diergent, paralelel or converging.
Then palpate both ishial spines and see whether diameter is adequate or not
Then down to the pubis and feel that.
And then between the ishial tuberosities...must be able to place a fist there.
And then angle of the pubic arch = whether acute or not.
When shold the assessment be done?
Primigravida ⇒ 37 weeks onwards
Milti para tried and tested vaginally can do in labour since known
Types of pelvis
ROP
Most commonly found in abnormal pelvis types like android
Malposition and not malpresentation
ROP is more cmmon than LOP because left is occupied by the sigmoid colon
OP is more common in primigravida..everything else is more common in multipara
Causes because more space posterioir and more in posterioir to fill up
FHS in LOA and ROA best heard misway between umbilicus and iliac spine
So ROP diagnosis clinically 1. Abdominal exam findings 2. Deflexed head findings 3. PV exam findings
In ROP engagent is delayed because head isnt well flexed
And then Pv exam can also reinforce this
Mechanism of labor in ROP position
Unfavourable outcome of ROP
Majority of these two types of labour will get a ceasarian section -
Intrumnetal delivery conditions is hard to meet in this case.
Perineal injury more because OF diameter is larger than the usual birthing diameter
And head is deleivered first y flexion and thn by extension to deliver face
Only in those kinds of pelvix have face to pubis delivery. Otherwise ceasarian,
Face and brow presentation
face presentation is diagnosed per vaginally
face presentation can be confused with frank breech. mouth with anus. cheeks with sacrum.
delivery of face occurs by flexion unless theres a neck or pelvic obtsacle
RMP and lmp in 20 converts tp ma like how ROP converts to OA but onl in minority of cases
Brow presentation by itself is an unstable presentation...and vaginally delivery not possible becase no diameter beats 14 cm
